Electric switch.



' Patented Mar. 25, |902.

n. rmmslmLL,i ELECTRIC SWITCH.

(Application led En. 18, 1901.) (No Model.)

@mi M UNITED STATES PATENT OFFICE.

NORMAN MARSHALL, OF NEWTON, MASSACHUSETTS, ASSIGNOR TO MAR-SHALL-SANDERS COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORA- TION OFMAINE.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent N o. 696,180, dated March25, 1902.

Application filed March 18, 1901. Serial No. 51,801. (No model.)

To all whom, t may concern:

Be it known that I, NORMAN MARSHALL, of Newton, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements Y in Electric Switches, of which the following is aspecification.

The invention relates to electric switches; and its object is to providean electric switch which may be readily operated by authorized personsand which may be put into such condition that its operation byunauthorized persons is prevented. This is accomplished by theemployment, in connection with the usual parts and mechanism of aswitch, of a locking means which may be operated by a key in thepossession of an authorized person and when so operated will prevent themovement or operation of the switch by unauthorized persons.- I preferto so construct the locking means that it may be adjusted by the actionof the key to hold the switch in either of two positions or may beadjusted so that operation of the switch will not be interfered with incase it is desired to leave the switch in condition to be operated bypersons having no key.

The features of invention may be embodied in'various forms of switches,the key-contrclledlocking mechanism being modified to suit the variedconditions.

In explaining the invention more fully I will refer to a simple andefficient construction of locking mechanism adapted to coperate with theparts of push-button switches and which embodies certain features ofinvention in addition to the broad features above referred to. Thismechanism comprises a rocker-arm the ends of which engage or areconnected with the reciprocating arms which operate the switchmechanism, so that the rocker-arm is rocked by the movement of eitherarm in operating the switch, and a keycontrolled stop for holding therocking arm from movement.

In the accompanying drawings, in which I have shown this mechanism andso much of a push-button switch as is necessary to show the cooperationbetween said mechanism and the mechanism of the switch, Figure l is aplan view of the face-plate of a push-button switch, showing the facelof the locking mechanism. Fig. 2 is an enlarged sectional View throughthe tumbler of the locking mechanism, showing a key adapted to lit theform of tumbler shown. Fig. 3 is a side elevation of the lockingmechanism with the face-plate and tumbler removed, the mechanism beingin position not to interfere with the operation of the switch. Fig. 4 isa similar view including the face-plate and tumbler and with the lockingmechanism in position to prevent the operation of the switch. Fig. 5 isan end View looking toward the right in Fig. 3. Fig. 6 is a plan view ofa part of the switch-supporting frame, showing the top of thelockingstud. Fig. 7 is a sectional View through one of the push-buttons,and Fig. Sis a bottom view of the1 button and the arm to which it issecured.

The various part-s of the switch are supported upon the usual frame L,having afront plate for securing the same in place, and the face-plate Ais arranged to fit over the frame in the usual manner, the plate beingperfo-v rated for the passage of the push-buttonsB B', by which theswitch mechanism is operated.

The buttons B B are of a simple and inexpensive construction, beingformed of two cups of sheet metal, one iitting within the other andsecured together in any suitable manner, as by soldering, brazing, or byfrictional engagement. As shown in Figs. 7 and 8, the cup or shell B, ofmetal, closely lits over the shallow cup D, the parts being firmly heldtogether by friction or by soldering or brazing. The cup D is drawn upin its center, as at E, and is screw-threaded to receive the screw C, bywhich the button is secured to the arm F of the switch. By thisconstruction a cheap, light, and strong button is provided suitable foruse in connection with push-button. switches.

"at J, and the reciprocating arms, to which the buttons are secured, areindicated at F, while the remaining well-known parts of the switch areomitted from the drawings. The operation of this class of switch is wellunderstood, the button B being pushed in and the button B beingprojected when the parts of lhe switch are to be moved into a certainposition-intoposition to completeacircuit,forin stance-and thepush-button B' being pushed in and the button B projected when the partsale to be moved into another position--into position to break a circuit,for instance.

' The locking mechanism shown is constructed to prevent the operation ofthe switch when in either of two positions-that is, when the button B isin its inner position or when the button B is in its inner position.This locking mechanism consists of a rocker-arm H, one end of whichengages the button B and the other end of which engages the button B',and a stud G, constructed to form a stop for preventing the movement ofarm H and to be operated by a key. The rockerarm is pivoted to the frameL at K and is provided with an ear or projection N for cooperating withthe stop or locking-stud G. The stud G' is mounted to turn in the frontplate of the frame L and is cut away or slotted at M, so that the bottomof the slot or dat face of the stud forms a stop for engaging theprojection N on the rocker-arm when the stud is turned into the properposition. The parts are so arranged that when the stud G' is in theposition indicated in Fig. 3, with the engaging face of the studparallel with the plane of arm H, the projection N may move across saidface or through the slot M when the switch is operated and the operationof the switch will not be prevented. When the stud is turned into theposition shown in Fig. 4 or through an angle of ninety degrees, theengaging face of the stud is brought into the path of the projection Nand prevents the movement of the arm H, and consequently prevents theoperation of the switch. Vith this form of stop the projection N shouldextend to or beyond the center of the stud G', so that any pressureexerted by the projection N against the engaging surface of the studwill not turn said stud. In case it is desired to lock the switch withthe button B in its inner position, the stud G should be turned in anopposite direction from that indicated after the button B' has beenpushed in.

The stud G may be turned to lock the switch in either of the twopositions referred to or may be turned into the position indicated inFig. 3 by means of akey P, the form of which is determined by thetumbler G, which is mounted to turn in the face-plate A. The tumbler Gis provided with an enlarged part or flan ge which fits within arecessin the under surface of the plate, being held therein by swaging theplate, as indicated at Q, Fig. 2. In the simple form of the tumbler andkey indicated the tumbler is provided with two holes arranged toregister with a slot in the end of the stud G/ and the key P is providedwith two projections arranged to pass through the holes inthe tumblerand engage the slot in the stud, as indicated in Fig. 4. By insertingand turning the key in the proper direction after the switch has beenadjusted the operation of the switch may be prevented until the lockingmechanism is again operated by the person having the proper key in hispossession.

What I claim, and desire to secure by Letters Patent, is

l. In an electric switch the combination with devices for operating theswitch, of a key-controlled locking mechanism for preventing theoperation of the switch embodied in and forming part of the switch.

2. In an electric switch the combination with mechanism for operatingthe switch, of a key controlled locking mechanism constructed to locksaid switch in either of two positions.

3. In an electric switch the combination with reciprocating push-buttonsfor operating the switch, of a key-controlled locking device forpreventing the movement of said pushbuttons.

4. In an electric switch the combination with reciprocating push-buttonsfor operating the switch, ot a key-controlled locking device constructedto prevent the movement of said push-buttons when the switch is ineither of two positions.

5. In an electric switch the combination with reciprocating devices foroperating the switch, of a rocker-arm connected with said devices, and akey-controlled stop for preventing the movement of said arm.

6. In an electric switch the combination with reciprocating devices foroperating the switch, of a rocker-arm connected with said devices, aprojection on said arm, a key-controlled stud provided with an engagingsurface arranged to be moved into or out of the path of said projectionby the rotation of' said stud.

7. In an electric switch the combination with the switch-operatingdevices, of a rockerarm connected to move therewith, a lockingstud forpreventing the movement ot' said arm, and means whereby the stud may beoperated by a key.

8. In an electric switch the combination with the push-buttons connectedto operate the switch, of a rocker-arm connected with said pushbuttons,aprojection on said rockerarm, a stud having a stop-surface arranged tobe turned into and out of the path of said projection, means wherebysaid stud may be turned by a key, and a tumbler for determining the formof the key.

9. A button for a push-button switch comprising two metallic shellsIitting one within the other, one of said shells being drawn up IOO atits center and screw-threaded to receive :L VIn testimony whereof I haveaffixed my sigseeuringsorew nature in presence of two Witnesses.

10. A button for a push-button switch eom` prisng a. metallic shell orcup B, a cup D fit- 5 ting Within the open end of said shell and'Vitnesses:

having its Center drawn up and sereW-thread- E. M; BAKER, ed at; E. lIRA- L. FISH.

NORMAN MARSHALL.`

